Digital radios have been introduced to enable reception of a new digital radio spectrum that provides improved fidelity, as well as additional features. Currently in the United States, digital radio is available over-the-air using sidebands to an analog carrier signal. The current system as commercialized in the United States is referred to as so-called HD™ radio. By way of these sidebands, a broadcaster can provide one or more additional complementary channels to an analog carrier signal.
Accordingly, digital or HD™ radios can receive these signals and digitally demodulate them to provide a higher quality audio signal that includes the same content as an analog radio signal, or to provide additional content to the analog radio signal such as supplementary broadcasting available on one or more supplemental digital channels.
Typically, a digital radio tuner is incorporated in a radio solution that also includes a conventional analog spectrum receiver for handling demodulation of the analog carrier signal. In a digital radio for use in a home or automobile environment, demodulation for both the analog and digital signals can run concurrently, as power consumption is not a concern. However, in a portable device, excessive power consumption by the digital demodulator can adversely affect battery life, particularly as a digital signal may not always be available.